At around 1 p.m. Wednesday, less than a week before today's crucial primary vote, a few hundred supporters lined up outside Duncanville High School, about 15 miles south of Dallas. Buttons were sold, three for $12. Shirts too, $10 each. Three hours later, the packed gymnasium of more than 2,500 -- with at least 500 more stuck outside -- spontaneously erupted into chants. The right side yelled, " B ARACK!" The left side screamed, " OBAMA!"

The candidate had yet to take the stage.

And down on the floor stood Rhonda Friedberg, a roll of duct tape encircling her right arm like a loose bracelet. A slender, striking woman with more than a passing resemblance to Diane Keaton, Friedberg calls herself "the tape lady." She's taped signs in restrooms, posters on walls and electrical wires to the floor so people don't trip.

This has been a season of many "firsts" for the 46-year-old molecular biologist: the first time she's volunteered for a campaign, the first time she's served as a precinct captain in an election, the first time she's given money to a candidate.

Every time Friedberg drives her 1991 red Toyota pickup truck out of the driveway of her Dallas home to attend another meeting of Obama's precinct captains, she surprises even herself. Before, she was "a homebody," as her husband of seven years describes her. Now, she feels she's part of a movement.

"Whether or not he wins the nomination, whether or not he makes it all the way to the White House, this is a movement," Friedberg shouts above the roar of the crowd. "A movement is when you're emotionally involved, and that's where I am."

She pauses, then says "And, you know, it's not about Barack Obama. It's about us. He's expressing what we need expressed and what we've been needing expressed for years."

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Rep. John Lewis knows movements. A lion of the civil rights cause, he endured nearly fatal blows in his fight against segregation in the 1960s.

Last Wednesday, the day of Obama's Duncanville rally, was the 48th anniversary of the first time the young Lewis was arrested for sitting at a lunch counter that didn't serve blacks. That anniversary was also the day that Lewis switched his support from Clinton, a longtime friend, to Obama, the first truly viable African American presidential candidate. Lewis's district and state -- Georgia -- voted overwhelmingly for Obama.

"I think what is happening today is the dreams, the hopes, the aspirations, the longing of a people being realized," Lewis said yesterday in an interview. "His rise is the most moving and exciting political movement that I've seen in my lifetime."

To Obama's critics, especially those who support Clinton, another historic candidate, his campaign is a mere cult of personality. To them, Obama is little more than a man of words and speeches floating on a thin r¿sum¿.

But whether a movement or a cult, Obama's political techniques have reshaped the presidential campaign landscape in ways few could have foreseen.

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Michael Kazin, a history professor at Georgetown University, says the term "movement" is typically linked to a cause, not a campaign or a candidate. Leaders of movements are usually defined by causes they've led (the farm workers' movement, the antiwar movement, etc.). And they're usually outsiders to the establishment, not a part of it. Think the Rev. Martin Luther King Jr.

Movements, however, support candidates, the way the antiwar movement aided Sen. Eugene McCarthy in the 1960s. And because of his early opposition to the Iraq war, Obama finds himself leading a liberal movement that's been expanding in the last few years, explains Kazin, author of "The Populist Persuasion: An American History."

Henry Jenkins, director of the Comparative Media Studies Program at MIT, uses Frank Capra's classic film "Mr. Smith Goes to Washington" to explain the dual reactions toward Obama. If you dislike him, Jenkins says, the fear is that he's the Huey Long figure who manipulates the emotions of the people and turns them into a mob. But if you like Obama, Jenkins adds, then he stands for the Jefferson Smith character who articulates the sentiment of the people who've been locked out of the process.

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Obama's movement began online, at least according to supporters such as Friedberg.

It was online that she first gave $100 to his campaign last year, followed months later by another $50. It was on Obama's Web site that she studied his stance on issues: health care, Social Security, the environment, education. It was on YouTube that she watched his speeches and found Will.I.Am's "Yes, We Can" viral video hit.

Ask Friedberg about the moment, the exact moment, she realized she was voting for Obama and all she can tell you is, "I don't know. I found it all online." She only turns on her television to watch DVDs.

Friedberg isn't alone. Like-minded supporters have largely funded Obama's campaign, allowing Obama to top the prodigious Clinton fundraising machine and push his movement-style message in ads, in mailers, through door knockers and the like. A few days ago, Obama crossed the millionth online donor mark, a feat that Sen. John Kerry, the 2004 Democratic nominee, barely achieved before the convention.

Then there's his popularity on social networking sites. Not just on YouTube and Facebook but also on LinkedIn, the soc-net of choice for many higher-income professionals, and BlackPlanet, the MySpace for African Americans. Online, a movement formed by a diverse electorate has grown.

And then there's his own Web site, which adapted Howard Dean's 50-state strategy to garner support not just from reliably blue states but also from traditionally red ones. On Texas.barackobama.com, the biggest grass-roots volunteer groups (Austin for Obama, San Antonio for Barack Obama, etc.) were created on Feb. 10, 2007, the day Obama announced his White House bid.

Simon Rosenberg, a veteran of the Clinton war room and founder of the New Democrat Network, says the Clinton campaign found itself stuck in the 20th-century model of campaigning: the 30-second TV spot, a tarmac stop and 200 kids in the headquarters. What Obama has been better at, Rosenberg explains, is understanding an emerging 21st-century model: Every day, because of the Internet, supporters work for their candidates, contacting their friends on various sites, sending e-mails, watching and creating videos and forwarding them online. It is movement politics in which a messenger (Obama) clicks with a medium (the Internet), Rosenberg says.

"The Clinton campaign missed the zeitgeist of the moment," Rosenberg says, "and they underestimated the possible reach of Obama's support, and they're paying for it."

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If you wanted to know what a movement looks like, supporters of Obama say, go to his events. The size of the crowds speaks for itself. Clinton, too, can draw a crowd, just as she did in El Paso on the night she decisively lost three states to Obama during the Potomac Primary. Some 12,000 people went to see her -- more the exception than the rule.

Obama, meanwhile, has consistently packed them in. More than 18,000 showed up in Houston's Toyota Center two weeks ago. That same week in Dallas, about 17,000 filled Reunion Arena, and thousands were turned away. At the Fort Worth Convention Center last Thursday, 13,000 stood in hour-long lines to get seated.

Finally, at around 8 p.m., the crowd at Fort Worth got to see who they came for.

"Hello, Texas!" Obama beamed.

Robert Ramirez, 35, dragged his wife, Sandy, 32, to the rally. Ramirez already saw Obama in Dallas, but he wanted Sandy to see him, too. Both voted for President Bush in 2000 and again in 2004. It was that year, watching the Democratic National Convention on television, that Ramirez remembered taking note of Obama. "What you realize being here is, it's not just about him, not just about one individual," says Ramirez, a post office clerk. "What makes him powerful is us, all of the people here together." He's given $10 to Obama, his first-ever political contribution. For a man with four kids facing rising gas prices, $10 is three gallons.

Sheila Johnson, 32, has donated $150 so far, also her first political contribution. It was her first time seeing Obama. She left work an hour early to get to the rally on time. Standing inside, surrounded by a throng of strangers of all ages, colors and backgrounds, the human resources manager says: "For me, in my lifetime, it is truly possible that an African American man can be the president of the United States of America. My family, my mother, my aunts, my uncles, might get to see that in their lifetime. That makes me almost want to cry just thinking about it."

"So I owe it to them, and if not to myself," she continued, "to be here to hear him speak because of everything that we've worked for as a community. That makes it a movement to me."

And there was "the tape lady," that roll of duct tape on her arm. Never mind the gladioluses and calla lilies that need planting in her small front yard. Forget the novel she picked up about two months ago.

Over the past month, Friedberg's priority has been to make sure Obama's supporters in her precinct know about the Texas two-step: First they have to vote in the primary, then show up at 7 p.m. for the caucus.

By Monday morning, she'd made more than 700 phone calls on Obama's behalf. Being inside the arena, enveloped in the roar of the crowd, listening to Obama and his promises of hope and change, she feels part of something.